The present disclosure pertains to a vehicle drive device.
In one known system, a drive controller for an electric vehicle is provided with a slip detection apparatus that calculates the acceleration of the vehicle wheels from the rotation speed of a drive motor, and determines the presence of wheel slippage from the wheel acceleration. The acceleration of the vehicle body based on the torque command value of the drive motor is then determined. A torque control apparatus reduces the torque of the torque command value sent to the drive motor when the presence of wheel slippage is determined by the slip detection apparatus. The torque control apparatus also implements control such that the torque command value sent to the drive motor becomes a normal running command value according to the operation amount of the accelerator pedal when slippage of the wheels is not detected by the slip detection apparatus. Thereby, smooth running is targeted on a road having low frictional resistance.
Incidentally, it is also known that a transaxle containing a speed reducer and a differential gear is connected to the drive motor mounted in the electric vehicle. The driving force of the drive motor that is input into the transaxle is distributed to the left front wheel and the right front wheel via left and right front wheel axles. Accordingly, on split-μ roads having different road surface friction on the left and right sides of a vehicle, and the like, when the presence of slippage of the left front wheel or the right front wheel is detected by the slip detection apparatus, the drive controller reduces the torque of the torque command value sent to the drive motor. Therefore, both the torque distributed to the left front wheel and the torque distributed to the right front wheel are reduced. In other words, the total drive torque of the front wheels is reduced, and ample drive torque appropriate for the demands of the driver cannot be transmitted to the road surface.
The present disclosure takes into consideration the above problem, and seeks to provide a vehicle drive device that can thoroughly transmit ample driving torque and braking torque to the road surface appropriate for the demands of the driver even on split-μ roads having different road surface friction on the left and right sides of a vehicle.